The present invention relates to a servo-control device for steering an articulated vehicle including a tractor and at least one trailer with wheels with fixed or articulated axles, and control means to give this device a steering set-point, this device including a first detector for detecting the position of the guiding wheels of the tractor vehicle, at least a second detector for detecting the position of the trailer relative to the axis of the tractor vehicle and an electronic circuit for providing the servo-control device with a control signal for steering the front wheels of the tractor as a function of information provided by the first and the second detectors and the steering set-point given by the control means.
A device of this type which is already known is described in the international patent application published under number WO 85/03263.
In this patent application, there are essentially described the different servo-controls acting on the steering control to principally facilitate maneuvers in reverse motion of articulated vehicles of the half-trailer type or of the truck type towing a trailer.
It is proposed in the present invention to define a number of improvements of this device to ensure its sure and efficient operation under all circumstances. One of the objectives sought when maneuvering this type of vehicle is precise positioning of the trailer with respect to a fixed obstacle such as for example the corner of a road, the door of a shed, or the edge of a loading ramp.